Researchers have examined the role of diversity, political opportunity, economic factors, and exclusion from executive power on interethnic conflicts. However, there is a lack of research to explain the impact of ritual behavior on interethnic conflicts. I use comparative historical research to focus on the role of religious rituals in Turkey and Iran by applying the following criteria of Randall Collins’ Interaction Ritual Model; bodily co-presence, barriers to outsiders, a mutual focus of attention, and shared mood. The descriptions of the rituals come from sociological, anthropological and religious works. In this research, I also use data from PEW and other research centers on the rate of participation in rituals such as visiting shrines, rate of pilgrimage participation, and other variables. In addition, I used the extant survey datasets on religious and ethnic relations in both countries. Iran and Turkey are two predominantly Muslim and ethnically diverse countries where people practice religious rituals. In this research, I investigated the effect of practicing Sunni rituals in Turkey and Shia rituals in Iran on interethnic relations among the ethnicities that share the same rituals. Since intensity and components of the rituals differ from each other, the potency of them to create social cohesion varies. Through analyzing the rituals and social cohesion in Iran and Turkey, I found a strong association between intensity of the religious rituals and interethnic social cohesion. Shia rituals in Iran are more intense, and because of that there is a high degree of social cohesion among Shia ethnicities. Contrarily, Sunni rituals in Turkey are not intense, and because of that the Sunni ethnicities in Turkey have a weak social cohesion. This study helps to understand the dynamics of interethnic conflicts and the political implications of religious rituals in Muslim societies.